WO2001025301A1

WO2001025301A1 - Liquid composition polymerizable into photochromatic organic glass

Info

Publication number: WO2001025301A1
Application number: PCT/EP2000/008872
Authority: WO
Inventors: Luciana Crisci; Maria Lucia Wis; William Giroldini; Vincenzo Malatesta
Original assignee: Great Lakes Chemical (Europe) Gmbh
Priority date: 1999-10-01
Filing date: 2000-09-11
Publication date: 2001-04-12
Also published as: ITMI992047A0; ITMI992047A1; IT1313659B1

Abstract

Liquid composition polymerizable, by means of radicalic polymerization, into photochromatic organic glass, comprising a polymerizable allyl carbonate, a polymerization initiator capable of generating free radicals under the polymerization conditions and a photochromatic compound.

Description

LIQUID COMPOSITION POLYMERIZABLE INTO PHOTOCHROMATIC ORGANIC GLASS.

The present invention relates to a liquid composi- tion polymerizable into photochromatic organic glass.

More specifically, the present invention relates to a liquid composition polymerizable, by means of radicalic polymerization, into photochromatic organic glass having good optical and physico-mechanical characteristics, comprising a polymerizable allyl carbonate, a polymerization initiator capable of generating free radicals under the polymerization conditions and a photochromatic compound.

A further object of the present invention relates to the photochromatic organic glass obtained by the polymerization of said composition and the end-products ob^¬ tained starting from this composition such as, for exam^¬ ple, ophthalmic and safety plates and lenses.

Photochromatic compounds are substances which have the characteristic of reversibly changing color and/or de- gree of light transmission when exposed to certain types of electromagnetic radiation and solar light, returning to their original color and transmission state when the initial light source is removed. There are numerous substances with photochromatic characteristics, which belong to various groups of both organic and inorganic compounds such as, for example, those described in the texts "Photochromism", by G.H. Brown (Ed.), Vol. Ill of the Weissberger series "Tech- niques of Organic Chemistry", Wiley Interscience, New York (1971) ; "Photochromism: Molecules and Systems", by H. Diirr and H. Bouas-Laurent (Ed.), Vol. 40 of the series "Studies in Organic Chemistry" Εlsevier (1990) .

Among organic photochromatic compounds, those belong- ing to the groups of spiro-indoline-oxazines, spiro-pyrans and chromenes, are particularly known and used.

The above compounds are capable of giving photochromatic characteristics to polymerized organic materials which can be used in the production of photochromatic ar- tides as described, for example, in the following patents: EP 315,224, EP 442,166, EP 432,841, EP 524,692, EP 245,020, U.S. 5,005,576, U.S. 5,110,922, U.S. 3,567,605 and U.S. 5,066,818.

The above organic photochromatic compounds can also be used in the field of organic glass, in particular when said organic glass is used for the preparation of photochromatic optical articles.

Various polymers which can be used for the preparation of organic glass for the optical industry, are known in the art. Among these, for example, polyacrylates, polycarbonate, cellulose acetyl butyrate, polystyrene and polyurethanes, can be mentioned. Among the types of organic glass of considerable commercial importance, is that deriving from the polymerization of allyl carbonates of diols or polyols, as described, for example, by F. Stein in: "Encyclopedia of Chemical Processing and Design", I Ed. Dekker. Inc., New York (1964), page 452 onwards; or in European patent EP 35,304.

Numerous methods are known in literature, for intro- ducing photochromatic organic compounds into materials generally defined as organic glass.

The methods described consist, for example, in introducing a suitable layer of material, containing the photochromatic substance, between two layers of organic glass. This method however is difficult and costly and, furthermore, as the end-products obtained consist of different materials joined by means of adhesives, they tend to lose their structural unity or, in any case, the good properties characteristic of organic glass. Another method consists in the surface impregnation of organic glass by immersing the glass in a solution of the photochromatic substance in an organic solvent using a technique similar to the color bath method ("dip-dyeing") . The drawbacks of this technique consist in the use of or- ganic solvents which are often flammable, the very lengthy immersion times and the possibility of damaging the organic glass during the long contact with the solvent.

Alternatively, the photochromatic compound can be applied by means of thermal transfer as described, for exam- pie, in European patent EP 316,980, or by transfer in vapor phase. Also these methods, however, have various drawbacks: the photochromatic compound, in fact, remains localized in the surface layers of the end-product and is therefore subject to the degrading action of atmospheric agents.

Other methods consist in dispersing the photochromatic compound in paints or resins which are then deposited on the surface of the lens or organic glass in general. These systems also have the disadvantages described above: complexity, high cost and often limited performances and, in addition, as it is known that the fatigue strength depends on the quantity of photochromatic compound used, end-products with a limited duration are ob- tained with the above methods. It is known, on the other hand, that end-products obtained by the polymerization of a monomer widely used in the organic glass industry such as diethyleneglycol bis (allyl carbonate) , known under the trade-name of CR 39^® of PPG Industries or RAV 7^® of Great Lakes Chemical Corporation, in the presence of a photochromatic compound belonging to the group of spiro-indoline-oxazines or spiro-pyrans, do not have a photochromatic activity due to degradation of the active principle as a result of the radicalic polymerization initiators normally used such as, for example, di-isopropyl percarbonate, dicyclohexyl per- carbonate and dibenzoyl peroxide. This inconvenience, however, is not surprising for experts in the field, as it is known that almost all organic dyes used in the preparation of colored organic glass, do not resist the drastic polymerization conditions to which the diethylene-glycol- bis (allyl carbonate) is subjected.

The first to overcome the disadvantages of the known art described above are Italian patent IT 1,255,878 and European patent application EP 595,424.

Italian patent IT 1,255,878 describes the preparation of photochromatic organic glass with a high refractive index by means of the radicalic polymerization of a urethane resin of the acrylate and/or methacrylate and/or styrene type. The photochromatic compounds belonging to the groups of spiro-pyrans, spiro-oxazines and chromenes, are introduced into the monomeric mixture and do not seem to undergo significant degradation during the polymerization. However, even if the end-products thus obtained have good photochromatic characteristics, this preparation has a drawback relating to the high increase in the production costs due to the resin used.

Numerous preparations based on acrylates and styrene matrixes containing photochromatic products in mass, have been described in the last few years, but very few based on allyl carbonates.

A further great improvement with respect to the known art consists of European patent application EP 595,424 mentioned above, which describes a polymerizable liquid composition which is also useful for the preparation, by means of mass polymerization, of photochromatic organic glass. This composition, consisting of a poly (allyl carbonate) of an aliphatic or cycloaliphatic polyol, must be polymerized using initiators of the peroxide type belong- ing to the group of perketals.

The polymerizations carried out using the above composition and radicalic initiator, proceed without any substantial degradation of the photochromatic compound or organic dye introduced into the polymerizable mixture. The use, however, of spiro-indolino-naphtho-oxazines and spiro-indolino-quino-oxazines known in the art, having position 6 of the naphthalene or quinoline ring free, causes, after polymerization, a bright and persistent reddish-purple coloring in the organic glass which strongly reduces the initial transmittance of the organic glass and makes it aesthetically unacceptable.

This is due to the fact that, as described for example in "Journal of Organic Chemistry" (1995), Vol. 60, pages 5446-5448, when the above position 6 is free, the C=C double bond undergoes a radicalic addition to give stable adducts having a reddish-purple coloring.

As most spiro-indolino-naphtho-oxazines and spiro- indolino-quino-oxazines having a blue coloring in the activated state, have position 6 free, they give a bright coloring every time they are used in mass polymerization. This greatly limits the possibility of obtaining photochromatic organic glass based on polyallyl carbonate, having a neutral (gray or brown) coloring: this coloring is mainly requested in the field of ophthalmic lenses in which the photochromatic compounds or organic dyes are directly present in the polymerization mixture.

The Applicant has now surprisingly found that the use of particular compounds belonging to the group of spiro- isoindolino-oxazines do not give the above bright and per- sistent reddish-purple coloring. This allows even blue photochromatic compounds to be used in a mixture with other products to obtain liquid compositions polymerizable into photochromatic organic glass having neutral shades . An object of the present invention therefore relates to a liquid composition polymerizable, by means of radicalic polymerization, into photochromatic organic glass, comprising a polymerizable allyl carbonate, a po^¬ lymerization initiator capable of generating free radicals under the polymerization conditions and a photochromatic compound, characterized in that:

(A) said polymerizable allyl carbonate is at least a poly (allyl carbonate) of an aliphatic C₂-Cij polyol, linear or branched, or of a cycloaliphatic C₅-Ci polyol, said polyols containing from 2 to 6 hydroxyl groups in the molecule, said poly (allyl carbonates) being in the form of monomers or mixtures of monomer and relative oligomers;

(B) said polymerization initiator, capable of generating free radicals, is at least a compound selected from the group of perketals;

(C) said photochromatic compound is at least an organic photochromatic compound selected from the group of spiro-isoindolino-oxazines . Component (A) As indicated above, allyl carbonates useful for the purposes of the present invention are poly (allyl carbonates) of aliphatic polyols containing from 3 to 10 carbon atoms in the linear or branched chain. Poly (allyl carbon- ates) of cycloaliphatic polyols containing from 5 to 16 carbon atoms in the molecule can also be used for the purpose. These polyols may generally contain from 2 to 6 hydroxyl groups in the molecule, preferably from 2 to 4. Mixed poly (allyl carbonates) can also be used, i.e. de- riving from two or more polyols, which can be obtained by the mechanical mixing of poly (allyl carbonates) of the single polyols, or directly by chemical reaction starting from diallyl carbonate and from a mixture of polyols, as specified hereunder in greater detail. Finally, all the above poly (allyl carbonates) can be in the form of a monomer, or a mixture of the monomer with the relative oligomers. The poly (allyl carbonates) (A) are generally products which are liquid at room temperature, with a viscosity ranging from 10 cst to 500 cst, measured at 25°C and their oligomer content can vary within a wide range, for example, from 0% to about 80% by weight.

In accordance with what is described above, examples of poly (allyl carbonates) (A) which can be used for the purposes of the present invention are: - bis (allyl carbonates) of diols such as, for example, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1, 3-propanediol, 1,4- butanediol, 1, 5-pentanediol, 1, 6-hexanediol, neopen- tyl glycol, 3-methyl-l, 5-pentanediol, 2-methyl-2- ethyl-1, 3-propanediol, 2, 2-diethyl-l, 3-propanediol, 2, 2, 4-trimethyl-l, 3-pentanediol, 1, 4-dimethylolcy- clohexane, 4, 8-bis (hydroxymethyl) [5.2.1.0^2-6] tricyclo- decane, etc.; tris (allyl carbonates) of triols such as, for exam- pie, glycerol, trimethylolpropane, tris (hydroxy- ethyl) iso-cyanurate, etc:; tetra (allyl carbonate) of pentaerythritol; hexa (allyl carbonate) of dipentaerythritol; mixed bis (allyl carbonates) of at least two diols selected from those listed above; mixed poly (allyl carbonates) of at least one diol and at least one polyol selected from those specified above.

Preferred examples of poly (allyl carbonates) (A) useful for the purposes of the present invention are listed below.

(i) bis (allyl carbonate) of diethylene glycol monomer or mixture of monomer and relative oligomers.

The bis (allyl carbonate) (i) monomer can be defined by the following general formula: CH₂ __CH-CH₂ -0-C-0_R-0-C-0_CH₂ _CH=CH_a

' : — I ¹ ^ n

wherein R represents the radical of diethylene glycol and n = 1. The bis (allyl carbonate) (i) can be prepared by the reaction of diethylene glycol bis (chloroformiate) with allyl alcohol as described, for example, in "Encyclopedia of Chemical Technology", Kirk-Othmer, III Ed., Vol. 2, pages 111-112. The bis (allyl carbonate) (i), mixture of monomer (n = 1 in the above general formula) with one or more oligomers (n from 2 to about 10 in the above general formula) , can be simply and conveniently prepared by means of a transesterification reaction between diallyl carbon- ate and diethylene glycol, operating in the presence of a base catalyst as described, for example, in European patent EP 35,304. Said monomer/oligomer mixtures may generally contain up to 80% by weight of oligomers. (ii) bis (allyl carbonate) of neopentyl glycol monomer or mixture of monomer and relative oligomers.

The bis (allyl carbonate) (ii) is similar to that of (i) described above, with neopentyl glycol substituting diethylene glycol. (iii) mixed poly (allyl carbonate) of diethylene glycol and tris (hydroxyethyl) isocyanurate . The mixed poly (allyl carbonate) (iii) can be obtained by the transesterification of diallyl carbonate with a mixture of diethylene glycol and tris (hydro- xyethyl) isocyanurate as described, for example, in U.S. patent 4,812,545.

(iv) mixed poly (allyl carbonate) of neopentyl glycol and tris (hydroxyethyl) isocyanurate. The mixed poly (allyl carbonate) (iv) is similar to that of (iii) described above, with neopentyl glycol sub- stituting diethylene glycol.

(v) mixed poly (allyl carbonate) of 1, 4-butanediol and tris (hydroxyethyl) isocyanurate. The mixed poly (allyl carbonate) (v) is similar to that of (iii) described above, with 1, 4-butanediol sub- stituting diethylene glycol.

(vi) mixed poly (allyl carbonate) of diethylene glycol and pentaerythritol described, for example, in European patent application EP 302,537. (vii) tris (allyl carbonate) of trimethylol propane, ob- tained by the reaction of diallyl carbonate with trimethylol propane under transesterification conditions . (viii) tetrakis (allyl carbonate) of pentaerythritol, ob^¬ tained by the reaction of diallyl carbonate with pentaerythritol under transesterification condi- tions .

Suitable transesterification conditions are described, for example, in European patent EP 35,304 mentioned above. Component (B)

Perketals which can be used as polymerization initiators for the purposes of the present invention are compounds known in the art and belonging to the group of gem-diperoxides having the following general formula:

R ' OOR' ' ' C _R* . ^OOR' ' '

wherein R' ' ' represents a tertiary alkyl group, preferably t-butyl or t-amyl; R' and R' ' each independently rep- resent an alkyl group such as, for example, methyl, ethyl, propyl and butyl, said alkyl group optionally carrying non-interfering functional groups such as, for example, an ester alkyl group at the chain end; or R' and R^{, !}, jointly with the carbon atom to which they are bound, form a cycloalkylene group, preferably a cyclohex- ylidene group, said cycloalkylene group optionally substituted with one or more alkyl groups, preferably with 1-3 methyl groups.

Specific examples of gem-diperoxides useful for the purposes of the present invention are: 2,2-di-(t- butylperoxy) butane, n-butyl-4, 4-di (t-butylperoxy) valer- ate, ethyl-3, 3-di (t-butylperoxy) valerate, 1, 1-di- (t-bu- tylper-oxy) cyclohexane, 1, 1-di (t-butylperoxy) -3, 3, 5-tri- methylcyclohexane, etc. Cyclic gem-diperoxides and cyclic gem-triperoxides such as, for example, 3, 3, 6, 6-tetramethyl-l, 2, 4, 5- tetraoxane, 3, 6-diethyl-3, 6-dimethyl-l, 2,4, 5-tetraoxane, 7, 8, 15, 16-tetraoxadispiro [5.2.5.2.] hexadecane; 3, 3, 6, 6, - 9, 9-hexamethyl-l, 2, 4, 5-tetraoxycyclononane, etc., can also be used for the purposes of the present invention.

The perketal (B) is present in the compositions object of the present invention in a quantity ranging from 0.5 to 5.0 parts, preferably from 0.8 to 2.5 parts by weight, for every 100 parts by weight of component (A) . Component C

Photochromatic compounds useful for the purposes of the present invention are selected from the group of spiro-isoindoline-oxazines having the following general formula (I) :

wherein :

R represents a linear or branched Ci-Cio alkyl group, said alkyl group optionally substituted with 1-10 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Ci~C₆ alkoxyl groups, carboxyl groups, cyano groups, or with a 2,2,6,6- tetramethylpiperidine group; a vinyl group; an allyl or methallyl group; a linear or branched C₂-C₀ alkenyl group; an aryl group selected from phenyl, biphenyl and naphthyl, said aryl group optionally substituted with linear or branched Ci-Ce alkoxyl groups, carboxyl groups, amine groups, N,N-dialkyl (Ci-Cβ) amine groups; a COOR' ester group wherein R' represents a linear or branched Ci-Cio alkyl group; a benzyl group, said benzyl group optionally substituted with 1-5 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched C_-Cι₀ alkyl groups, linear or branched Ci-Cε alkoxyl groups, carboxyl groups, cyano groups, or with a 2,2,6,6- tetramethylpiperidine group; - Ri and R__., the same or different, represent a linear or branched Ci-Cio alkyl group, said alkyl group optionally substituted with 1-10 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpipe- ridine group; a vinyl group; an allyl or methallyl group; a linear or branched

alkenyl group; a COOR' ester group wherein R' represents a linear or branched Ci-Cio alkyl group; a benzyl group, said benzyl group optionally substituted with 1-5 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Ci-Cio alkyl groups, linear or branched Cι~C₆ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpipe- ridine group; a linear or branched Cι~C₅ alkoxyl group; an N-alkyl (Cι~C₆) amine group; an N,N- dialkyl (C-C₆) amine group; or, R_ and R_c, jointly with the carbon atom to which they are bound, represent a C₄-C₁0 cycloalkyl group, said cycloalkyl group optionally substituted with halogen atoms selected from fluorine, chlorine and bromine, or with hy- droxyl groups, linear or branched Cι-C₆ alkoxyl groups, carboxyl groups, cyano groups, amine groups, N-alkyl (d-C₆) amine groups, N,N-dialkyl (Cι-C₆) amine groups, N,N-dialkyl (Cι-C₆) amide groups, aryl groups selected from phenyl and biphenyl;

R₃, 4, R5 and R₆, the same or different, represent a hydrogen atom; a halogen atom selected from fluorine, chlorine, bromine and iodine; a linear or branched Cι-C₆ alkyl group, said alkyl group option- ally substituted with 1-6 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Cι~ Cό alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpiperidine group; a benzyl group, said benzyl group optionally substituted with 1-5 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched C1-C1 alkyl groups, linear or branched Cι-C₆ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpiperidine group; a hydroxyl group; a linear or branched Cι-C₆ alkoxyl group; an amine group; an N- alkyl (Cι-C₅) amine group; an N,N-dialkyl (Ci-Ce) amine group; a piperidine, piperazine or morpholine group; a Ci-Cβ carboxyalkyl group; a C-C6 car- boxyalkenyl group; a carboxyamine group; N-alkyl (Cι-C₆) carboxyamine group; an N,N-dialkyl (Ci-Ce) carboxyamine group; a cyano group; a nitro group; a sulfonic group; an aryl group selected from phenyl, biphenyl and naphthyl, said aryl group optionally substituted with N,N-dialkyl (Cι-C₆) amine groups, linear or branched Cι-C₆ alkoxyl groups, hydroxyl groups, linear or branched Cι-C₅ alkyl groups; an acyl group of the alkyl ketone, aryl ketone or benzyl ketone type; a linear or branched C;-C₆ alkenyl group, said alkenyl group optionally substituted with one or two N,N-dialkyl (Ci-Ce) -4-aniline groups; an N-2, 3-dihydroindoline group; a linear or branched Cι-C₅ thioether group; two consecutive substituents between R₃ and R₆, can represent the condensation points with other aromatic, heterocyclic or quinonic rings; - R7 represents a hydrogen atom; a halogen atom selected from fluorine, chlorine and bromine; a linear or branched C_-C_δ alkyl group; a linear or branched Ci-Cβ alkoxyl group; a phenyl group, a phenoxyl group; - P represents a monocyclic or polycyclic aromatic nu- cleus, belonging to one of the following types: ben^¬ zene represented by general formula (II) ; naphtha^¬ lene represented by general formula (III) ; quinoline represented by general formula (IV) ; isoquinoline represented by general formula (V) ; cumarine repre^¬ sented by general formula (VI) ; quinazoline repre^¬ sented by general formula (VII) ; phenanthrene represented by general formula (VIII) ; anthracene repre^¬ sented by general formula (IX) ; or a heteroaromatic system represented by general formula (X) :

R ^■4. 7 R ^•4. 2 .

wherein : at least two consecutive substituents between R₈ and R13, R1 and R21, R22 and R₂β , R30 and R35 R36 and R_, R44 and R47, R48 and R57, R58 and R₆7, ROB and R75, rep^¬ resent the condensation points with the oxazine ring, the other substituents having the same mean^¬ ings as substituents R₃, R₄, R≥ and R_ό described above;

Y represents a CH₂; an oxygen atom; a nitrogen atom; a sulfur atom; or a selenium atom. Preferred compounds having general formula (I) for the purposes of the present invention, are those wherein:

R represents one of the following groups: methyl, ethyl, isopropyl, 2-allyl, 2-hydroxyethyl, 2- carboxymethyl, phenyl, 4-N,N-dimethylaminoaniline, 4-methoxybenzene, 4-cyanobenzene;

Ri and R₂, the same or different, represent a methyl or phenyl group; or, considered jointly with the carbon atom to which they are bound, represent a cy- clohexyl group, - R₃, R₄, R₅ and R₆, the same or different, represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or one of the following groups: methyl, isopropyl, hydroxyl, methoxyl, N,N- di ethy1amine, piperidine, morpholine, carboxyl, carboxymethyl, N,N-dimethylcarboxyamide, cyano, ni- tro, methylketone, phenylketone, phenyl; R₇ represents a hydrogen atom, a chlorine atom, a bromine atom, a methyl group or a phenyl group;

P represents one of the groups having general for- mula (II) to (X), wherein:

(a) two consecutive substituents between R₈ and R_i3, R14 and R21, R22 and R?8 R30 and R35, R36 and R_i, R44 and R47, R43 and R57, R58 and R_δ7, Res and R75. represent the condensation points with the ox- azine ring and the other substituents each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or one of the following groups: methyl, isopropyl, hydroxyl, methoxyl, 2-hydroxyethyl, 2-allyl, piperidine, morpholine, N,N-dimethylamine, car^¬ boxyl, carboxymethyl, N,N-dimethylcarboxyamide, cyano, nitro, methylketone, ethylketone, phen^¬ ylketone, methylthiol;

(b) two consecutive substituents between R₈ and R_i3, R1 and R , R22 and R28. R30 and R35, R36 and R₄_, R44 and R47, R48 and R57, Rse and R₆7, R_δ8 and R₇₅, different from those specified under point (a) , represent the melting points with a benzene or quinone ring; (c) Y represents an oxygen atom.

In the polymerizable liquid composition of the present invention, component (C) is used in a quantity ranging from 0.01 to 0.5 parts by weight, preferably in a quantity in the order of 0.1 parts by weight per 100 parts by weight of component (A) .

The composition object of the present invention may optionally contain one or more conventional additives such as, for example, oxidation, light and heat stabilizers, lubricants, dyes, pigments, ultraviolet light ab- sorbers (UV-absorbers) , infra-red radiation absorbers (IR-absorbers) , and the like, in a total quantity however of not more than 1 part by weight for every 100 parts by weight of the compositions themselves.

Examples of additives which can be used for the pur- poses of the present invention are: sterically hindered phenols, sterically hindered amines, benzophenones, ben- zotriazoles, organic phosphites and phosphonites, etc.

The composition object of the present invention containing the polymerization initiator and, optionally, one or more additives selected from those mentioned above, is transformed into the relative organic glass, operating at a temperature ranging from 30°C to 120°C, with polymerization times which generally vary from 1 hour to 100 hours . The composition object of the present invention allows photochromatic organic glass with good optical characteristics to be obtained, particularly useful in the production of optical articles such as ophthalmic and safety plates and lenses; these end-products therefore form an additional object of the present invention.

The following components were used in the following experimental examples which further illustrate the invention. Component (A) The component (A) used, hereinafter indicated as component (Ai) , is the product obtained by the reaction of diallyl carbonate (DAC) with a mixture of neopentyl glycol (NPG) and tris (hydroxyethyl) isocyanurate (THEIC), in the following proportions: NPG 70% by weight; THEIC 30% by weight; molar ratio DAC/ (NPG+THEIC) = 5/1.

The product thus obtained is a complex mixture containing: a) bis (allyl carbonate) of neopentyl glycol, having the following general formula (monomers and oligomers) :

the following composition: monomer (n = 1) 82% by weight; dimer (n = 2) 15% by weight; trimer (n = 3) 2.4% by weight; tetramer (n = 4) 0.4% by weight; and the following physico-chemical characteristics: viscosity, 25°C (cst) = 53; density, 20°C (g/ml) = 1.096; - n_D ^2& •= 1.4525; b) tris (allyl carbonate) of tris (hydroxyethyl) isocyanurate (monomer and oligomers) having the following general formula:

Cr « ^xO

CH.-o^-o-c-o— ax, -αtcH-

O

c) mixed allyl carbonates of neopentyl glycol and tris (hydroxyethyl) isocyanurate having the following physico-chemical characteristics : viscosity, 25°C (cst) = 80; - density, 20°C (g/ml) = 1.1411; n_D ²⁰ = 1.4525;

Component (B)

The component (B) used, hereinafter indicated as component (Bi) , is 1, 1-di (t-butylperoxy) -3, 3, 5-trimethyl- cyclohexane [1.5 parts by weight for every 100 parts by weight of component (Ai) ] . Component (C)

The component (C) used is selected from the following spiro-isoindolino-oxazines having the following formulae (Ci) - (C₅) :

The above compounds having formula (Ci)-(C₅) are prepared as described, for example, in Italian patent appli- cation IT MI97A/01573.

The above compounds (Ci)-(C₅) are compared with two known compounds : compound (D_x) having the formula:

known under the trade-name of VARIACROL BLUE D of Great Lakes Chemical Corporation; compound (D₂) having the formula:

obtained as described, for example, in European patent application EP 432,841.

The neutral photochromatic lenses, object of the following experimental examples, are prepared by means of the procedure described below.

The polymerizable liquid compositions are prepared by mixing and homogenizing the allyl carbonate (Ai) , the polymerization initiator (B_x) in the quantity indicated in the examples and, subsequently, the photochromatic compounds (Ci)-(C₅) and (Dι)-(D₂), again in the quantities indicated in the examples .

The compositions thus obtained are transformed, by means of polymerization, into neutral lenses with a thickness of 2 mm, by means of the conventional "casting" technique. According to this technique, the liquid composition containing the catalyst is poured into the cavity of a mould consisting of two glass elements separated by a seal made of plasticized polyvinyl chloride (PVC) or eth- ylene-vinyl acetate (EVA) copolymer.

The composition is subjected to polymerization in the mould by means of the following thermal treatment, of a duration of 24 hours, in a forced air circulation oven: regulated at 70°C to 90°C in 3 hours, from 90°C to 95°C in 2 hours, isotherm at 95°C for 19 hours.

At the end of the above thermal treatment, the moulds are opened and the following characteristics are determined on the neutral photochromatic lenses thus ob^¬ tained:

(a) (λ_max UVA) of the deactivated form and (λ_r3X vis.) of the activated form;

(b) photochromatic activity expressed as ΔY which corresponds to the difference between the Luminous Trans^¬ mittance values (Y) , before and after activation with a UVA lamp, radiation equal to 9 W/irr, 60 sec^¬ onds of radiation;

(c) lens color in the deactivated and activated form ex^¬ pressed with the colorimetric values L^", a^* and b^*

(D65, 10^*) as defined in Regulation CIE 1976. These values are obtained by mathematical processing of the absorption spectrum.

The following experimental examples are provided for illustrative purposes but do not limit the scope of the present invention. EXAMPLES 1-7

Compositions are prepared, containing 98.5% by weight of Component (A_x) and 1.5% by weight of component (Bi) . Quantities equal to 0.1% of the total of photochromatic compounds (Dι)-(D₂) (Examples 1-2) and (Cι)-(C;) (Examples 3-7) , described above, are added each time to the composition.

The liquid compositions thus obtained are subjected to polymerization according to the conditions described above. Photochromatic lenses are obtained, whose proper- ties are indicated in Table 1, whereas Figure 1 and Figure 2 illustrate the transmittance spectra of the deactivated form of said photochromatic lenses.

The values of L^*, a^* and b^* indicated in Table 1 relating to lenses in the deactivated form, Figure 1 and Figure 2 clearly demonstrate how the lenses obtained using the photochromatic compounds (Dι)-(D₂) (Examples 1-2) known in the art, unlike the lenses obtained using the photochromatic compounds (Cι)-(C₅) (Examples 3-7) according to the present invention, have an intense absorption between 500 nm and 580 nm corresponding to a bright pur- pie coloring.

10

15

20

25 Table 1

Claims

1. A liquid composition polymerizable, by means of radicalic polymerization, into photochromatic organic glass, comprising a polymerizable allyl carbon- ate, a polymerization initiator capable of generating free radicals under the polymerization conditions and a photochromatic compound, characterized in that:

(A) said polymerizable allyl carbonate is at least a poly (allyl carbonate) of an aliphatic C-Cι_C polyol, linear or branched, or of a cyclo- aliphatic C₅-Cι_δ polyol, said polyols containing from 2 to 6 hydroxyl groups in the molecule, said poly (allyl carbonates) being in the form of monomers or mixtures of monomer and relative oligomers;

(B) said polymerization initiator, capable of gener^¬ ating free radicals, is at least a compound se^¬ lected from the group of perketals;

(C) said photochromatic compound is at least an or- ganic photochromatic compound selected from the group of spiro-isoindolino-oxazines.

2. The polymerizable liquid composition according to claim 1, wherein the poly (allyl carbonates) (A) are selected from: - bis (allyl carbonates) of diols such as, dieth- ylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1, 3-propanediol, 1, -butanediol, 1, 5-pentanediol, 1,6- hexanediol, neopentyl glycol, 3-methyl-l, 5- pentanediol, 2-methyl-2-ethyl-l, 3-propanediol,

2, 2-diethyl-l, 3-propanediol, 2,2, 4-trimethyl- 1,

3-pentanediol, 1, 4-dimethylolcyclohexane, 4, 8-bis (hydroxymethyl [5.2.1.0^2-6] tricyclodeca- ne; - tris (allyl carbonates) of triols such as, glycerol, trimethylolpropane, tris (hydroxyethyl) isocyanurate, etc:; tetra (allyl carbonate) of pentaerythritol; hexa (allyl carbonate) of dipentaerythritol; - mixed bis (allyl carbonates) of at least two diols selected from those listed above; mixed poly (allyl carbonates) of at least one diol and at least one polyol selected from those specified above. The polymerizable liquid composition according to claim 2, wherein the poly (allyl carbonates) (A) are selected from:

(i) bis (allyl carbonate) of diethylene glycol monomer or mixture of monomer and relative oligomers. (ii) bis (allyl carbonate) of neopentyl glycol monomer or mixture of monomer and relative oligomers . (iii) mixed poly (allyl carbonate) of diethylene gly- col and tris (hydroxyethyl) isocyanurate.

(iv) mixed poly (allyl carbonate) of neopentyl glycol and tris (hydroxyethyl) isocyanurate. (v) mixed poly (allyl carbonate) of 1,

4-butanediol and tris (hydroxyethyl) isocyanurate. (vi) mixed poly (allyl carbonate) of diethylene glycol and pentaerythritol. (vii) tris (allyl carbonate) of trimethylol propane, obtained by the reaction of diallyl carbonate with trimethylol propane under transesterifi- cation conditions.

(viii) tetrakis (allyl carbonate) of pentaerythritol, obtained by the reaction of diallyl carbonate with pentaerythritol under transesterification conditions . The polymerizable liquid composition according to any of the previous claims, wherein the perketals (B) which can be used as polymerization initiators belong to the group of gem-diperoxides having the following general formula: R ' OOR ' ' ^■ C _R . . OOR ' ^■ '

wherein R' ' ' represents a tertiary alkyl group, preferably t-butyl or t-amyl; R' and R' ' each inde- pendently represent an alkyl group such as, methyl, ethyl, propyl and butyl, said alkyl group optionally carrying non-interfering functional groups such as, an ester alkyl group at the chain end; or R' and R'', jointly with the carbon atom to which they are bound, form a cycloalkylene group, said cycloalkylene group optionally substituted with one or more alkyl groups, preferably with 1-3 methyl groups.

5. The polymerizable liquid composition according to claim 4, wherein the perketals (B) are: 2,2-di-(t- butylperoxy) butane, n-butyl-4, 4-di (t-butylperoxy > valerate, ethyl-3, 3-di (t-butylperoxy) valerate, 1,1- di- (t-butylperoxy) cyclohexane, 1, 1-di (t-butylperoxy) 3,3, 5-trimethylcyclohexane .

6. The polymerizable liquid composition according tc claim 1, wherein the perketals (B) are selected from cyclic gem-peroxides and cyclic gem-triperoxides .

7. The polymerizable liquid composition according to claim 6, wherein the perketals (B) are: 3,3,6,6- tetramethyl-1, 2,4, 5-tetraoxane, 3, 6-diethyl-3, 6-di- methyl-1, 2, 4, 5-tetraoxane, 7, 8, 15, 16-tetraoxadispi- ro [5.2.5.2. ] hexadecane; 3, 3, 6, 6, -9, 9-hexamethyl- 1,2,4, 5-tetraoxycyclononane .

8. The polymerizable liquid composition according to any of the previous claims, wherein the perketal (B) is present in a quantity ranging from 0.5 to 5.0 parts for every 100 parts by weight of component (A) .

9. The polymerizable liquid composition according to any of the previous claims, wherein the photochro- matic compounds (C) are selected from the group of spiro-isoindoline-oxazines having the following general formula (I) :

wherein: - R represents a linear or branched C_.-Cιo alkyl group, said alkyl group optionally substituted with 1-10 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2,2,6,6- tetramethylpiperidine group; a vinyl group; an allyl or methallyl group; a linear or branched C -C alkenyl group; an aryl group selected from phenyl, biphenyl and naphthyl, said aryl group optionally substituted with linear or branched Cι-C₅ alkoxyl groups, carboxyl groups, amine groups, N,N-dialkyl (Cι-C_δ) amine groups; a COOR' ester group wherein R' represents a linear or branched Ci-Cio alkyl group; a benzyl group, said benzyl group optionally substituted with 1-5 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Cι-C__. alkyl groups, linear or branched Cχ-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpiperidine group ;

Ri and R₂, the same or different, represent a linear or branched Ci-Cio alkyl group, said alkyl group op^¬ tionally substituted with 1-10 halogen atoms se^¬ lected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpiperidine group; a vinyl group; an allyl or methal- lyl group; a linear or branched C2-C10 alkenyl group; a COOR' ester group wherein R' represents a linear or branched C₁-C₁0 alkyl group; a benzyl group, said benzyl group optionally substituted with 1-5 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Ci-Cio alkyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethyl- piperidine group; a linear or branched Cι-C alkoxyl group; an N-alkyl (Cι-C₆) amine group; an N,N- dialkyl (Cι~C_δ) amine group; or, R_ and R2, considered jointly with the carbon atom to which they are bound, represent a C4-C10 cycloalkyl group, said cy- cloalkyl group optionally substituted with halogen atoms selected from fluorine, chlorine and bromine, or with hydroxyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, amine groups, N-alkyl (Cι-C_δ) amine groups, N,N-dialkyl (Ci-Cδ) amine groups, N,N-dialkyl (Cι-C_δ) amide groups, aryl groups selected from phenyl and biphenyl;

R, R, R5 and R₆, the same or different, represent a hydrogen atom; a halogen atom selected from fluorine, chlorine, bromine and iodine; a linear or branched Cι~C_δ alkyl group, said alkyl group optionally substituted with 1-6 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is se- lected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpiperidine group; a benzyl group, said benzyl group optionally substituted with 1-5 halogen atoms selected from fluorine, chlorine and bromine, or with C(X)₃ groups wherein X is selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched C1-C10 alkyl groups, linear or branched Cι-C_δ alkoxyl groups, carboxyl groups, cyano groups, or with a 2, 2, 6, 6-tetramethylpiperidine group; a hydroxyl group; a linear or branched Ci-Ce alkoxyl group; an amine group; an N-alkyl (Ci-Cβ) amine group; an N,N-dialkyl (Cι-C_δ) amine group; a piperidine, piperazine or mor- pholine group; a Cι-C₆ carboxyalkyl group; a C₂- C_s carboxyalkenyl group; a carboxyamine group; N-alkyl (Cι~C_δ) carboxyamine group; an N,N- dialkyl (Cι-C_δ) carboxyamine group; a cyano group; a nitro group; a sulfonic group; an aryl group selected from phenyl, biphenyl and naph- thyl, said aryl group optionally substituted with N,N-dialkyl (Cι-C_δ) amine groups, linear or branched Cι~C_δ alkoxyl groups, hydroxyl groups, linear or branched Ci~C_δ alkyl groups; an acyl group of the alkyl ketone, aryl ketone or benzyl ketone type; a linear or branched C₂- C_δ alkenyl group, said alkenyl group optionally substituted with one or two N,N-dialkyl (d- C_δ) -4-aniline groups; an N-2, 3-dihydroindoline group; a linear or branched Cι~C_δ thioether group; two consecutive substituents between R and R_δ, can represent the condensation points with other aromatic, heterocyclic or quinonic rings;

R₇ represents a hydrogen atom; a halogen atom selected from fluorine, chlorine and bromine; a linear or branched Cι-C₆ alkyl group; a linear or branched Cι-C₆ alkoxyl group; a phenyl group, a phenoxyl group; P represents a monocyclic or polycyclic aromatic nucleus, belonging to one of the following types: benzene represented by general formula (II) ; naphthalene represented by general formula (III) ; quinoline represented by general formula (IV) ; isoquinoline represented by general formula (V) ; cumarine represented by general formula (VI) ; qumazoline represented by general formula (VII); phenanthrene represented by general formula (VIII) ; anthracene represented by general formula (IX) ; or a heteroaro- matic system represented by general formula

25

wherein: at least two consecutive substituents between R₈ and R₁₃, R: and R21, R22 and R;e, R₃₀ and R35

R₃₆ and R_i, R4 and R47, R₄s and R₅-, R₅₃ and R_δ-, R_δ8 and R₇s. represent the condensation points with the oxazine ring, the other substituents having the same meanings as substituents R₃, R₄, R₅ and R_δ described above;

Y represents a CH₂; an oxygen atom; a nitrogen atom; a sulfur atom; or a selenium atom.

10. The polymerizable liquid composition according to claim 9, wherein the compounds having general for- mula (I) are those wherein:

R represents one of the following groups: methyl, ethyl, isopropyl, 2-allyl, 2-hydro- xyethyl, 2-carboxymethyl, phenyl, 4-N,N- dimethylaminoaniline, 4-methoxybenzene, 4-cya- nobenzene; Ri and R₂, the same or different, represent a methyl or phenyl group; or, considered jointly with the carbon atom to which they are bound, represent a cyclohexyl group, R3. 4. R5 and R₆, the same or different, represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or one of the following groups: methyl, isopropyl, hydroxyl, methoxyl, N,N-dimethylamine, piperidine, mor- pholine, carboxyl, carboxymethyl, N,N-dimethyl- carboxyamide, cyano, nitro, methylketone, phe- nylketone, phenyl;

R₇ represents a hydrogen atom, a chlorine atom, a bromine atom, a methyl group or a phenyl group;

P represents one of the groups having general formula (II) to (X), wherein:

(a) two consecutive substituents between R₈ and R13, R_i4 and R₂ι, R22 and R28. R30 and R35. R-36 and Rι, R₄ and R47, R₄s and R57, Rss and R_δ7, R_δ8 and R75, represent the conden^¬ sation points with the oxazine ring and the other substituents each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or one of the following groups: methyl, isopropyl, hydroxyl, methoxyl, 2-hydroxy- ethyl, 2-allyl, piperidine, morpholine, N,N-dimethylamine, carboxyl, car- boxymethyl, N,N-dimethyl-carboxyamide, cyano, nitro, methylketone, ethylketone, phenyl-ketone, methylthiol;

(b) two consecutive substituents between R₈ and R13, Ri and R-_ι, R₃: and R;₈, R₃- and R35, R_3δ and R41, R44 and R47, 3 and R_Ξ-, R=_ and R₆7, Res and R75, different from those specified under point (a) , represent the melting points with a benzene or quinone ring; (c) Y represents an oxygen atom.

11. The polymerizable liquid composition according to any of the previous claims, wherein component (C) is used in a quantity ranging from 0.01 to 0.5 parts by weight per 100 parts by weight of component (A) .

12. The polymerizable liquid composition according to any of the previous claims, containing one or more conventional additives such as, for example, oxidation, light and heat stabilizers, lubricants, dyes, pigments, ultraviolet light absorbers (UV- absorbers), infra-red radiation absorbers (IR- absorbers) , and the like, in a total quantity however of not more than 1 part by weight for every 100 parts by weight of the compositions themselves.

13. Photochromatic organic glass obtained by the polymerization of the liquid composition according to any of the previous claims.

14. Optical articles, such as safety and ophthalmic plates and lenses obtained from the organic glass according to claim 13.